<!DOCTYPE html>
Test paint invalidation of column-span:all when background color changes.
Passes if there is a green square.
<div style="columns: 2">
  <div id="spanner" style="column-span: all; width: 100px; height: 100px; background-color: red"></div>
</div>
<script src="../../../resources/run-after-layout-and-paint.js"></script>
<script>
runAfterLayoutAndPaint(function repaintTest() {
  spanner.style.backgroundColor = 'green';
}, true);
</script>
